arm_abs_q15.c
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00001 /* ---------------------------------------------------------------------- 00002 * Copyright (C) 2011 ARM Limited. All rights reserved. 00003 * 00004 * $Date: 15. December 2011 00005 * $Revision: V2.0.0 00006 * 00007 * Project: Cortex-R DSP Library 00008 * Title: arm_abs_q15.c 00009 * 00010 * Description: Q15 vector absolute value. 00011 * 00012 * Target Processor: Cortex-R4/R5 00013 * 00014 * Version 1.0.0 2011/03/08 00015 * Alpha release. 00016 * 00017 * Version 1.0.1 2011/09/30 00018 * Beta release. 00019 * 00020 * Version 2.0.0 2011/12/15 00021 * Final release. 00022 * 00023 * -------------------------------------------------------------------- */ 00024 #include "arm_math.h" 00025 00052 void arm_abs_q15( 00053 q15_t * pSrc, 00054 q15_t * pDst, 00055 uint32_t blockSize) 00056 { 00057 uint32_t blkCnt; /* loop counter */ 00058 q31_t in1, in2, in3, in4; /* temporary input variables */ 00059 q31_t out1, out2, out3, out4; /* temporary output variabels */ 00060 00061 /*loop Unrolling */ 00062 blkCnt = blockSize >> 3u; 00063 00064 /* First part of the processing with loop unrolling. Compute 8 outputs at a time. 00065 ** a second loop below computes the remaining 1 to 7 samples. */ 00066 while(blkCnt > 0u) 00067 { 00068 /* C = |A| */ 00069 /* Read inputs */ 00070 in1 = (q31_t)*pSrc; 00071 in2 = (q31_t)*(pSrc + 1); 00072 in3 = (q31_t)*(pSrc + 2); 00073 00074 /* find absolute value */ 00075 out1 = (in1 > 0) ? in1 : __QSUB(0, in1); 00076 00077 /* read input */ 00078 in4 = (q31_t)*(pSrc + 3); 00079 00080 /* find absolute value */ 00081 out2 = (in2 > 0) ? in2 : __QSUB(0, in2); 00082 00083 /* store result to destination */ 00084 *pDst = (q15_t)out1; 00085 00086 /* find absolute value */ 00087 out3 = (in3 > 0) ? in3 : __QSUB(0, in3); 00088 00089 /* read input */ 00090 in1 = (q31_t)*(pSrc + 4); 00091 00092 /* find absolute value */ 00093 out4 = (in4 > 0) ? in4 : __QSUB(0, in4); 00094 00095 /* store result to destination */ 00096 *(pDst + 1) = (q15_t)out2; 00097 00098 /* read input */ 00099 in2 = (q31_t)*(pSrc + 5); 00100 00101 /* find absolute value */ 00102 out1 = (in1 > 0) ? in1 : __QSUB(0, in1); 00103 00104 /* store result to destination */ 00105 *(pDst + 2) = (q15_t)out3; 00106 00107 /* find absolute value */ 00108 out2 = (in2 > 0) ? in2 : __QSUB(0, in2); 00109 00110 /* read input */ 00111 in3 = (q31_t)*(pSrc + 6); 00112 00113 /* store result to destination */ 00114 *(pDst + 3) = (q15_t)out4; 00115 00116 /* read input */ 00117 in4 = (q31_t)*(pSrc + 7); 00118 00119 /* find absolute value */ 00120 out3 = (in3 > 0) ? in3 : __QSUB(0, in3); 00121 00122 /* store result to destination */ 00123 *(pDst + 4) = (q15_t)out1; 00124 00125 /* find absolute value */ 00126 out4 = (in4 > 0) ? in4 : __QSUB(0, in4); 00127 00128 /* store result to destination */ 00129 *(pDst + 5) = (q15_t)out2; 00130 *(pDst + 6) = (q15_t)out3; 00131 00132 /* increment source pointer by 8 */ 00133 pSrc += 8u; 00134 00135 /* store result to destination */ 00136 *(pDst + 7) = (q15_t)out4; 00137 00138 /* increment destination pointer by 8 */ 00139 pDst += 8u; 00140 00141 /* Decrement the loop counter */ 00142 blkCnt--; 00143 } 00144 00145 /* If the blockSize is not a multiple of 8, compute any remaining output samples here. 00146 ** No loop unrolling is used. */ 00147 blkCnt = blockSize % 0x8u; 00148 00149 while(blkCnt > 0u) 00150 { 00151 /* C = |A| */ 00152 /* Read the input */ 00153 in1 = *pSrc++; 00154 00155 /* Calculate absolute value of input and then store the result in the destination buffer. */ 00156 *pDst++ = (in1 > 0) ? in1 : __QSUB16(0, in1); 00157 00158 /* Decrement the loop counter */ 00159 blkCnt--; 00160 } 00161 } 00162
